This invention relates to wheelchairs, and more particularly to apparatus for mounting the drive wheels of wheelchairs while imparting customized camber and toe adjustments to such wheels, and in particular to the wheels of sports wheelchairs.
The use of wheelchairs for permitting participation of physically disabled persons in various sports activities has resulted in the need for wheelchairs having improved operational characteristics. At the same time, the optimization of such improvements varies with the requirements of the specific sports activity and the physical characteristics and capabilities of the wheelchair occupant. Such considerations are of particular concern with respect to wheelchair stability and maneuverability, characteristics which are determined in some measure by the positional relationship of the two large drive wheels of the wheelchair and the extent by which camber and toe of such wheels may be customized while maintaining structural integrity of the chair.
The typical wheelchair includes a frame to which two large drive wheels (generally hand-driven) are mounted for rotation, one on each side of the frame for supporting the frame along with one or two smaller front wheels. The larger drive wheels are generally set closer together at the top than at the bottom, a characteristic referred to as "camber". These rear drive wheels may be set so that they are closer together at the front than at the back, a condition known as "toe-in", whereas adjustment of the wheels so that they are closer together at the back than at the front is known as "toe-out"; as used herein, "toe" refers to toe-in and/or toe-out.
In the past, camber adjustments have been imparted to the drive wheels of sports wheelchairs by means of devices which are removably attached to the frame for imparting the full measure of the preselected camber to the wheels.